Torque testing device



Feb. 29, 1944. R, J, QHAPMAN 2,342,919

TORQUE TESTING DEVICE Filed April 3, 1943 2 Sheets-Sheet 1 CLI r1- v'r1-A nl fu- /0/ nll'li'l'l'lr)lll'l'l'w I Oxl-Z l O l V A i f- MV1- 23/I 22 O Jai? A l IW 36 l *1 2 lill1 F" 40 35 INVENTOR BY Roy rf C/uymzanM MQW ToRA/x Feb. 29, 1944. R

J. CHAPMAN TORQUE TESTING DEVICE Filed April 3, 1943 2 Sheets-Sheet 2 Il VMM! I INVENTOR.

T y Chellpman TTo/ENEM Patented Feb. 29, 1944 UNITEDy STATES PYIILN'I'rFFICE l l 'Y `2,342,919 .l i

TORQUE TESTING DEVICE Roy J. Chapman, Los Angeles, Calif. ApplicationApril e, 194s, serial N0. fierros,

10 Claims.

The present invention relates generally to apparatus for testing theaccuracy of whatare commonly known as torque wrenches in order to`check, from time to time, the eiciency of such wrenches in machine andlaboratory use.

Torque wrenches are now in extensive use for many purposes in factoriesand laboratories where it is essential that a torque pressure. shall beapplied to the work in definite foot and l:inch pounds. For continuedefllciency it isvveryvimportant not only that the wrenches be tested foraccuracy from time to time to avoid the possible results of mechanicalfailures, but alsofthat any apparatus used for this purpose shallitselfbe of a nature admitting of its ready test.

It is the primary object of the present invention to provide-a testingapparatus or mechanism which is capable of ready, convenient andene tiveuse to test both right and left handltorque of torque wrenches, andwhich is itself of anature permitting ready test of its own efficiencyto offset possible inaccuracy due to climatic or other natu ralconditions or mechanical failure.

More particularly it is an object ofv theipresent invention to provide anormallyv balancedj'beam scale mechanism which is readily adaptable tobe read in foot pounds tofcorrespond to the wrench dials; which is of anature capable of beingreadily and easily tested in respect to its footpound indications, and which is adaptable to the ready `v easyassociation of a torque wrenchin a manner permitting test of eitherright or left hand torque, and also permitting a reading vthereof yinfoot pounds corresponding to the foot pound readings of the wrench dial.

In keeping with the foregoing, there has been pear in the course of thefollowing description. l However, the drawings merely show andthefollowing description merely describes one embodiment of the presentinvention, whichy is given by way of illustration or example only.

In the drawings, like reference characters designate similar parts inthe several views.

Fig. 1 is a perspective view of the invention illustrating its practicaluse.

Fig. 2 is an enlarged plan view looking down upon the torque wrench andshowing in section a portion of the testing mechanism engaged by thewrench during test thereof. e

Fig. 3 is a partial side view of the testing apparatus looking at theyopposite side thereof iwith respect to Fig. 1.

Fig. 4 is an enlarged broken away and in section, showing the pressureapplying means for engaging the wrench handle.

Fig., 5 is a vertical transverse sectional'view taken substantially online 5-5Hof Fig;` 4, parts being shown broken away, and

Figs. 6, 7 and 8 are detail perspective views, respectively, of thepressure jack,` Aits adjustable pressure head, and one of `itssupporting bars Referring to the above described figures of thedrawings, and particularly to Fig. 1,v there is shownabalance scaleincluding an upper balance beam lHl which is fulcrumedA adjacent to oneend `between the upperportions of spacedlstandards ll and is graduated'on both' faces in. foot and inch pounds as' seen in Figs. 1 and 3.)This'beam is equipped with'a sliding poise I2 andis balanced by standardweights I3 and I4 suitably hung by knife bearings I 5 at itsoppositefends and by a suitable adjustable counter-poised6.'j`

Aload beam Il below they balance beam I il;` has `its free end movablebetween the standards" I land is connected to the balance beam bysuitably joined knife bearing loops' I8 and l9. The other endrv of theload beam l'l has suitable'Qbearing.

preferably in ball bearings, through standards 3720 and at this endcarries frigid brackets 2| and'22 at opposite sides of said' standards20, each 'of which brackets hasta socket 23, in line with its bearing,to receive the implement engaging `head of the torque shaft of a torquewrench :fs'tandard manufacture, as presently describedjand ar'- rangedso that when a wrench is properly applied to the socket of eitherbracket, that is atleither side of the load beam, the wrench will'extendparallel with and along the load beam. f

The load beam Il is shown with a test loop 24 spaced twelve inches fromits bearingl between standards 20 so that by test weights on thisloopthat, in practice, this supporting* base .will be such that it may beassured yof a a level position for the extreme accuracy required in itstesting functions. j

detail side view, paruy A standard torque wrench 2E is shown in Figs. land 2 at one side of and parallel with' the load beam I1 by reason ofthe extension of its implement-engaging, torque shaft head 21 engaged inthe socket 23 of the beam bracket 2| (see Fig. 2), this being for thetest of right hand torque of the wrench. The wrench is shown with ahandle 28 and a meter or dial 2B which registers in foot and inch poundsthe pressure deflection of the handle 28, in use., withcrespect totheshaft `head 21.

An angular upright jack 3B is Shown with an adjustable jack screw 3|swiveled at its lower end in connection with a vertically adjustablepressure head 32. This pressure head 32 is held against rotation by aguide stem 33 slidable through the jack head in parallel relation to thejack screw 3|, so that when the latter is rotated, the pressure head 32is shifted vertically. At its lower portion the Yjack 30 has a slideway34 by which it is shiftable lengthwise of the load beam I1 so that itspressure head 32 maybe accommodated to the handles 28 of wrenches ofdifferent lengths, and also in order that it may be shifted from oneside of the load beam to the other side thereof.

For the above purpose a support for the jack is placed at each side ofthe load beam I1, each support consisting of a horizontal rail 35vlengthwise of, and below and parallel to, the load beam I1, with itsends rigidly supported in pedestals 3,6 ilxed on the base 25. Theslideway 34 of the jack is Vformed vto receive either of the rails 35between a lower angular flange 31 and an upper undercut shoulder `3.8.The flange 31.11as an upstanding pin -39, and each rail 35 has near oneend a lower notch 4.0 through which the pin .38 may be shifted inrocking the jack 3|) onto, and off of, either rail. Thus, the jack maybe applied to `one rail as in Fig. 1 when testing right hand torque ofthe wrench 26, and quickly removed and applied to the other rail whentesting left hand torque of the wrench, with the ,latter positioned atthecorresponding side of the load beam as above described.

`In operation, assuming the balance scale has lbeen leveled and properlytested, a wrench `2li may be applied, as previously described, with thepoise I2 adjacent to the fulcrum of ybalance beam I0 `at thezero mark 4|of the beam graduations.

VThe jack 3D is then shifted until the pressure head 32 is properlypositioned above the wrench handle 28, and the head run down onto thehandle, by means of the jack screw 3| until the meter or dial 29 showsthe foot or inch pressure at which `the rwrench is 'to be presentlytested. When this pressureonthe meter or dial'has been reached, thepoise I2 is shifted until hea-m I0 balances, it being understood thatthe pressure applied to the wrench handle has been communicated to theloadbeam' l1 through the head 21 of the torque shaft of the wrenchseated in the beam socketl 23, and from the load beam to the balancebeam I'U so as to unbalance vthe latter while the poise is at 'the zeropoint.

When the beam Ill has, in the above manner, been again brought intobalance, the graduation o n the balancebeam I should read in inch andfoot poundsprecisely as the meter or dial 29 of the wrench at that time.If th'e readings agree, the wrench tests, but if they do not agree, themechanism of the wrench must be removed and changed or adjusted `untilthey do agree.

It is believed to be plain from the foregoing that after thus testingthe right hand torque of the wrench' as in Fig. 1, the wrench isremoved, after releasing the jack, and switched to a similar positionwith respect to, and at, the other side of the load beam in similarengagement with the socket of the beam bracket 22. The jack is removedto the other rail 35 at the corresponding side, and the testing of theleft hand torque of the wrench is proceeded within the same manner aspreviously described for test of its right hand torque.

While I have illustrated and described what I now regard as thepreferred embodiment of my invention, the construction is, of course,subject to modifications without departing from the spirit andscope ofmy invention. I, therefore, do not wish to restrict myself to theparticular form of construction illustrated and described, but desirekto avail myself of all modifications that may fall within the scope ofthe appended claims.

Having thu-s described my invention, what I claim and desire to secureby Letters Patent is:

1. In a testing apparatus for a torque wrench having a torque meter, ascale mechanism including a balance beam having balancing weights andgraduations therealong in `accord with the Atorque `meter, a poiseslidable on said beam and balance the balance beam through the loadbeam.

2. The apparatus as set forth in claim 1, in which the coupling meansand the torque 'presn 'sure Aapplying means are effective at oppositesides of the load beam for similarly testing right and left hand wrenchtorque.

3. In a testing apparatus for a torque wrench 'having a torque meter, ascale mechanism in- `cluding la balance beam having balancing weights'and graduations therealong in accord with the torque meter, a poiseslidable on said beam and cooperating with the graduations thereof to-indicate degrees of unbalance of the beam, and a load beam having abearing adjacent to one end thereof and connected at its opposite end tothe balance beam to unbalance the latter beam in accord with loadapplied to the load beam, means for coupling the implement engagingelement of the wrench in torque communicating relation to saidload'beamin line with its said bearing, 'and means-adjacent thereto for applyingtorque pressure to a wrench when so coupled, to thus unbalance thebalance beam through the load beam, said 'last named means beingadjustable relative to the scale mechanism for accommodating wrenches ofdiiferent lengths.

4. In a `testing apparatus for a torque 4wrench having a polygonalimplement engaging member, and a torque meter, ra scale mechanismincluding a load beam having a bearing adjacent to one end thereof and alaterally opening polygonal socket inline with said bearing to receivethe polygonal implement engaging member of the wrench in torquecommunicating relation, a balance beam connected to the load beam in amanner to be balanced when the load beam is at rest and graduated inaccord with the torque meter of the Wrench, and an adjustable poisemember on said balance beam cooperating as an indicator with thegraduations thereof, and means yadjacent to said mechanism andadjustable for determining the degree of unbalance thereofv andgraduated to accord with the torque meter of the wrench, means to couplethe torque head of the Wrench in torque communicating rela tion to saidload beam in line with its pivot, whereby to unbalance the beam inaccord With torque pressure applied to the wrench, and means adjacent tosaid mechanism for applying torque pressure to the wrench When socoupled.

6. In a testing apparatus for a torque wrench having a torque head and atorque meter, a normally balanced torque measuring mechanism including apart graduated to accord with the torque meter, and an adjustableelement movable in cooperation with said part and its graduatons tocorrect and indicate unbalance thereof, means to couple the torque headof the wrench to said mechanism in torque communicating relation forun'balancing said graduated part in accord with torque pressure appliedto the wrench, and means adjacent to said mechanism for applying torquepressure to the Wrench when so coupled, said last named means including`a jack and a support for the jack on which it is adjusta-ble relativeto the torque measuring mechanism.

7. In a testing apparatus for a torque wrench having a torque head and atorque meter, a, normally balanced torque measuring mechanism includinga part graduated to accord 'With the torque meter, and an adjustableelement movable in cooperation With said part and its graduations tocorrect and indicate unbalance thereof,

' pivot to engage the torque head of the Wrench f l means to couple thetorque head of the wrench to relatively opposite sides of said mechanismin torque communicating relation. for unbalancing said graduated part inaccord with right hand and left hand torque pressure applied to theWrench, and means applicable to both sides of said mechanism forapplying torque pressure to the wrench to create unbalance of themecha#- nism to accord with the pressure so applied.

8. In a testing apparatus for a torque'wrench having a torque head and atorque meter, a pressure measuring mechanism having indicating meansgraduated in accord With the torque meter and including a pivotedmember, means fo-r-coupling the torque head of the wrench/in torquecommunicating relation with said pivoted member in line with its pivot,and means for applying torque pressure to the Wrench when so coupled, tothus similarly affect the torque meter of the wrench and the indicatingmeans of the' measuring mechanism. y*

9. In a testing apparatusfor a torque Wrench having a torque head and atorque meter, a movable member having a bearing and recesses at oppositesides of, and in line with, said bearing to receive the torque head ofthe Wrench in torque communicating relation, means shiftable torelatively opposite sides of said member to apply torque pressure to aWrench so associated with the member and to place the member under acorresponding load, and a balance mechanism connected with said memberand effective to indicate the load thereon.

10.` In a torque testing apparatus-for a torque wrench having a torquehead, supportingvmeans,

a load beam pivoted on said supporting means,

means carried by said load beam in' line withvits in torquecommunicating relation, meansarf ranged to be adjustable along a Wrenchso engaged, for applying torque pressure to the Wrench and place theload -beam under corresponding load, Iand load measuring and indicatingmeans in association with said load beam.

ROY J. CHAPMAN."

